| 초록 |
Chitosan particle-containing agar beads were prepared by dropping the suspension of agar/chitosan into cold distilled water. The beads were investigated in terms of morphology,loading efficiency,swellability,size and release property. The release from beads were observed for 6h using blue dextran and FITC-dextran as model drugs. While agar beads free of chitosan exhibited pH-indepentent release,chitosan particle-containing agar beads showed pH-depentent release. The release of blue dextran was less extensive at acidic pHs. On the contrary,the release of FITC-dextran was more extensive at acidic pHs. Positively charged chitosan seems to interact with negatively charged blue dextran at acidic pHs, leading to a suppressed release. On the other hand, electrostatic interaction between FITC-dextran and chitosan would hardy occur,because FITC-dextran is electrically neutral. At acidic pHs, FITC-dextran is likely to release through cavity,which is formed by leach-out of chitosan particles. |
